by: Stephen B. Blezinger
Ph.D., PAS

Part 3

This is part 3 of a series dedicated to a discussion on supplementation options and methods. In the last part of this series we discussed use of some commodities. We also began a discussion of manufactured supplements that are commonly used for this purpose. In this part we will continue this discussion as well as begin look at tools to perform an economic evaluation so the producer can determine which of the many methods are most cost effective.

Manufactured Feeds

c. Blocks and Tubs

Sometimes there is a little confusion on the terminology in this group. So let's take a moment to discuss. Blocks and tubs come in a variety of forms. Blocks are generally exactly that, a block of feed material formulated to a given set of nutrient specifications and can range in weight from 30 to 50 lbs. Some versions of blocks are produced in higher weight forms (i.e. 250 lbs). Some forms are molasses based. These are generally designed to be consumed in low quantities and convenience of supplementation is a primary focus. Blocks are generally high in protein (28-36 percent) a portion of which may come from non-protein nitrogen (urea). They can also be formulated to contain a significant amount of energy, minerals and vitamins.

Tubs are different from blocks in that they are commonly molasses or liquid by-product based. They are also poured into a container of some type prior to hardening. Again, this supplementation form is largely focused on convenience. Tubs are typically manufactured at higher weights (~225 to 250 lbs.) and are consumed at lower rates similar to blocks (1/2 to 2 lbs. per head per day). Consumption is typically controlled by the hardness of the supplement. Several manufacturing processes are used:

1) “Chemical” blocks – these blocks include components in the formulation that cause a chemical reaction that hardens the material after it is poured into the container. These blocks are fairly hard and control intake fairly well.

2) “Cooked” blocks – this process includes heating of the material. This is commonly included with a chemical process and produces a comparatively hard block. Again, this is a fairly effective method for controlling intake.

3) Poured blocks – as the name implies, the product is poured into the container and allowed to harden. Again, this form is closely related to chemical blocks.

4) Pressed blocks – the supplement material is put into the container and a certain amount of pressure is applied by a hydraulic press. In many cases this type of block is the softest and intake is higher.

In either case, the blocks ortubs can be formulated to contain a wide variety of nutrient profiles and so can range from being either simply a protein source to a fairly complete supplement including protein, energy, minerals and vitamins. They can also contain a variety of additives for improvement of feed efficiency, fly control, etc. These components have to be factored into the value of the supplement.

As mentioned previously, one of the primary purposes of blocks and tubs are convenience. Since intake is limited it is possible to place one or more of these supplemental “units” in the pasture with a group of cows and it will provide supplement for several days. It is important that if you choose this method that you know what the target intake is for the particular product and calculate the number of blocks needed for a given period of time. The producer also needs to recognize that if the cattle are hungry or if the forage base is low in quality or quantity, cattle will eat more of the supplement, regardless of the hardness of the block or tub.

This form also helps the producer feed without getting into the middle of the group of cows and potentially get knocked down and injured. Tubs or blocks can be dropped out of the back of the truck. Also, since the supplement is not fed daily and is available all the time (theoretically) the cattle will not bunch up around the pickup as readily.

Like all supplements, tubs and blocks are not fool-proof. Consumption is not controlled absolutely and variability will be noted. Secondly, this supplement form tends to be somewhat more expensive. So evaluation of cost is important.

d. Liquid Supplements

Liquids are commonly used as protein supplements. Like all supplements, liquids are available in a wide variety of formulations. Of the most common are formulations containing a protein content of 28 to 35 percent. Liquids have used higher levels of urea as a component of the protein. It is not uncommon at all to see a 32 percent protein liquid supplement that includes 28 to 30 percent of this protein provided as protein equivalent from the non-protein nitrogen in urea. Urea is a very useful nutritional tool for providing nitrogen to ruminants for the rumen bacterial population to convert to protein. Since consumption of excessive urea has created problems it is important that the producer feeds liquids properly and as directed. Urea is generally critical for liquids since most ingredients used in liquid supplements are relatively low in natural protein. Urea is also fairly cost effective for providing protein equivalence although urea cost has increased significantly along with other energy industry products and natural protein sources.

Liquids can be a good source of protein, minerals and vitamins. It's more challenging to manufacture liquids that are also good energy and calcium sources. Energy has typically been provided via the sugar content from the molasses or added fat. As molasses has escalated in cost and the sugar is being extracted for use in ethanol production less is available to the feed industry and thus there is a trend for lower levels of sugar to be available as an energy source. To compensate for this, the industry has included higher levels of fat and ingredients such as glycerol or propylene glycol. In general, however, liquid supplements are not considered to be a particularly good energy supplement. Significant amounts of calcium and fat can be included if a suspension agent such as attapulgite clay or xantham gum is used to prevent insoluble ingredients from settling out or fat products from separating/stratifying.

Liquids can also be delivery vehicles for additives such as ionophores, fly control and so on.

Liquid supplements are typically self-fed in open top troughs or lick wheel tanks. Most liquids are formulated to limit intake, generally one to three lbs. per head per day. Like tubs and blocks though, liquid intake is contingent on forage availability or quality. Hungry cattle or cattle fed low quality forages will consume higher amounts of supplement. This can be a problem for liquids which contain higher urea contents. That said it is important that cattle not be hungry when first introduced to liquid supplements to help prevent over consumption.

Liquid supplements are also very convenient to feed since the dealer they must be purchased from can deliver directly to your farm. Some dealers have also made small tote tanks available so producers can pick up the liquid at their convenience and fill their own tanks.

While liquids can be a cost effective form of supplement a couple of problems are common. One is related to intake. A producer decides to use a liquid supplement, and calculates what his cost will be as related to the projected intake. If his forage is not great or cattle are hungry as mentioned above, intake can be higher than expected resulting in more cost than expected. This situation has turned many producers off from using liquids. This is one reason why it is particularly important to understand all the circumstances prior to feeding a liquid.

A second perceived problem is that the producer has to purchase the feed troughs or tanks that hold the liquid for feeding. Many liquid feed dealers have run into significant resistance from potential customers concerning having to purchase these feeders. Unless you are feeding range cubes on the ground you have to have some means of feeding your supplement whether in troughs, self feeders, feed bunks, etc. Producers feeding cubes on the ground pay higher costs in terms of the loss they incur as discussed in Part 2 of this series. Tubs include the cost of the container. Blocks, fed on the ground, like cubes will incur some loss. No matter what supplementation form is used there is some additional cost involved.

Cost Analysis

Each producer has to determine which supplementation method works best for their operation. This means prioritizing the important factors as they apply to their specific operation. If cost is the only factor, this is relatively easy and will be discussed shortly. But for most producers other factors are involved. This might include labor availability or simple time management. Do you have the time to supplement daily by hand? Another is location. Some operations are spread out over miles and the distance does not allow for daily feeding. Yet another factor is safety. As mentioned before, many producers have been injured by trying to feed in a group of cattle. All these issues need to be taken into considerations.

So let's take a look at some cost comparisons for different supplement forms. The costs shown are averages and will differ significantly from area to area.

From this table we can see a range of costs and protein feeding rates. Some discussion:

The feeding rate for the cubes and range meal is very close. As is, the range meal is the cheaper option and since it is self fed allows for less labor and travel to the pasture to feed. A downside is that range meals with the high salt content are also lower in energy. However, if the protein requirements are being met the energy intake difference from the supplement may not be an issue.

At the shown feeding rate the poured block is the least expensive per day. And like the range meal is less labor and transportation intensive. It also allows the producer less contact with the cattle so the risk of injury is less. However, the amount of protein is also significantly lower. In order to feed the same amount of protein the cows would have to increase their consumption rate to 3.3 lbs. per head per day. The cost would then be $.90 per head per day so the cost advantage would be gone. This would be effective only if the hay or forage fed only required minor supplementation.

The liquid supplement at this cost would provide close to the same amount of protein daily as compared to the cubes or range meal and the cost is significantly lower. Plus there is the labor and transportation savings. But also like the range meal, the energy density of the liquid is lower so if energy is required this may be a negative.

As you can see, as has been said before, there are no perfect supplements. But these are certainly better alternatives depending on the situation on the farm. Taking the steps to evaluate priorities and costs are critical to making the best decision possible.


Making good supplementation decisions is not simple and involves weighing a variety of factors. We've gone through a number of points related to protein supplementation but this is only part of the picture. In part 4 of the series we will expand this discussion to energy and mineral and vitamin supplementation and opportunities and considerations.

Dr. Steve Blezinger is a nutritional and management consultant with an office in Sulphur Springs, TX. He can be reached by phone at (903) 352-3475 or by e-mail at sblez@verizon.net. You can also follow us on Facebook at Reveille Livestock Concepts.

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